When you attempt to flash the file, the recovery checks the last few bytes of the ZIP (the footer) for specific markers (like 0xff ) and then validates the cryptographic hash against its internal store. How to Use update-signed.zip There are two primary ways to apply these updates manually: 1. Via Local Update (System Settings)
To generate a release image, use: make dist sign_target_files_apks \ -o \ # explained in the next section --default_key_mappings ~ Android Open Source Project update-signed.zip
For an update to be accepted by a stock recovery, it must pass a "whole-file signature verification". When you attempt to flash the file, the
Developers often use the SignApk.jar tool to sign their own custom packages. update-signed.zip